Ni²⁺-zeolite/ferrosphere and Ni²⁺-silica/ferrosphere beads for magnetic affinity separation of histidine-tagged proteins

Abstract

Magnetic Ni(2+)-zeolite/ferrosphere and Ni(2+)-silica/ferrosphere beads (Ni-ferrosphere beads - NFB) of a core-shell structure were synthesized starting from coal fly ash ferrospheres having diameters in the range of 0.063-0.050 mm. The strategy of NFB fabrication is an oriented chemical modification of the outer surface preserving the magnetic core of parent beads with the formation of micro-mesoporous coverings. Two routes of ferrosphere modification were realized, such as (i) hydrothermal treatment in an alkaline medium resulting in a NaP zeolite layer and (ii) synthesis of micro-mesoporous silica on the glass surface using conventional methods. Immobilization of Ni(2+) ions in the siliceous porous shell of the magnetic beads was carried out via (i) the ion exchange of Na(+) for Ni(2+) in the zeolite layer or (ii) deposition of NiO clusters in the zeolite and silica pores. The final NFB were tested for affinity in magnetic separation of the histidine-tagged green fluorescent protein (GFP) directly from a cell lysate. Results pointed to the high affinity of the magnetic beads towards the protein in the presence of 10 mM EDTA. The sorption capacity of the ferrosphere-based Ni-beads with respect to GFP was in the range 1.5-5.7 mg cm(-3).

Composition, Structure, and Formation Routes of Blocklike Ferrospheres Separated from Coal and Lignite Fly Ashes

“…The use of process flow diagrams for separation and deep purification of FSs concentrates, which include granulometric, hydrodynamic, dry, and wet magnetic separation stages, enables classification of four known ash types, sialic (S), ferrisialic (FS), ferricalsialic (FCS), and calsialic (CS), into narrow FSs fractions of constant composition with the Fe 2 O 3 content in a range of 30–92 wt % and globule size in a range of 50–250 μm , and with reproducible magnetic properties. , The produced FSs fractions have the common composition–morphology–microstructure relationship for iron-containing phases, which, in turn, suggests their application areas as functional materials. FSs of constant composition can be used as effective catalysts for deep oxidation, oxidative coupling of methane, − thermolysis of heavy oils and oil residues, and magnetic carriers for affinity sorbents in protein separation …”

Magnetic Composite Sorbents for Trapping Heavy Metals from Liquid Waste and Their Immobilization in a Mineral-Like Matrix

“…Наличие в составе различных фракций ферросфер аморфной алюмосиликатной составляющей с содержанием от 15 до 62 мас. % дает возможность синтеза на поверхности ферросфер цеолитных фаз [15], обладающих ионообменными и сорбционными свойствами [16,17]. Другим вариантом получения инженерной формы магнитного сорбента может быть агломерация ферросфер с использованием цирконосиликатного связующего, выполняющего также функцию сорбционно-активного компонента и прекурсора фазы циркона.…”

Functionalized Nano-adsorbent for Affinity Separation of Proteins

“…The successful production and purification of full-length, soluble, and natural fusion proteins, however, are still retarded by various obstacles such as the need for pretreatment to remove the cell debris and colloid contaminants, a relatively long operation time, and protein solubility. These drawbacks, fortunately, could be overcame by applying nanomaterials to assist the separation and purification of the target proteins [15–19]. For example, magnetic SiO 2 -NiO nanocomposite is capable of separating His-tagged proteins [20].…”